Diagnostics is one area in dentistry in which enhanced skills continue to be needed. The main dental diagnostic tool, the dental explorer or probe, has been the mainstay in dental technology for diagnosing caries for over 150 years. Current methods of clinical examination include visualization and touch with the explorer. Both, however, can give false information. Currently, dentists tap on the teeth with the end of the dental explorer instrument to put a vibration into a tooth. By comparing the sounds these vibrations make a dentist can assess various conditions. A dentist can usually tell by the sound transmissions of these vibrations that something is not quite right. So much is based on the dentist's experience of listening and feeling of these vibrations. It is very subjective.
X-rays have been considered state of the art, but do not allow for early detection of incipient lesions. For example, leakage around the periphery of a filling cannot always be checked adequately with these methods. Further, these methods have not always proved satisfactory as to ascertaining the quality of tooth structure in all types of cavities, including Class I, II, III, IV, V, VI, and some types not classified in these groups such as crown margin caries, and intracanal caries. Although the current method of choice in dentistry to diagnose inter-proximal decay is with x-rays or radiographic interpretation, even given ideal circumstances, it has been shown that x-ray diagnosis is correct only about 30% of the time. Indeed, these methods are difficult for the inexperienced practitioner to achieve success as it generally requires years of clinical experience to master x-ray interpretation.
Ultrasonic devices have been used to detect smooth surface lesions (U.S. Pat. No. 6,162,177), jawbone cavitations (U.S. Pat. No. 6,030,221) and to evaluation root canal treatment (U.S. Pat. No. 5,115,813). For example, U.S. Pat. No. 7,175,599 discloses a method of diagnosing a subject by delivering ultrasound signals using shear waves includes applying a portion of an ultrasound mainbeam to a bone surface at an incident angle relative to the surface of the bone to induce shear waves in the bone, energy in the shear waves forming a substantial part of energy of first ultrasound waves at a desired region in the subject through the bone, detecting at least one of reflected and scattered energy of the applied ultrasound mainbeam, and analyzing the detected energy for a diagnostic purpose. However, such approach is expensive and not always possible due to skull geometry.
United States Patent Application 20030044755 discloses dental diagnosis by exploring a tooth surface or tooth material of a patient with a dental tool applying a known DC voltage to a localized region of the tooth surface area to locate a treatment area indicated by either a local lower resistance area surrounded by a higher resistance area, or a local higher resistance area surrounded by a lower resistance area; allowing for the assimilation of additional information needed for advanced treatment of the area being tested; verifying successful treatment of the treatment area by applying the dental tool with the known DC voltage to the treatment area and confirming the presence or absence of the local lower or higher resistance area; and permitting continuation of testing of the treatment area or a new treatment area, based upon those new findings. However, applying large electrical currents to human may not be safe, particularly if the patient is wearing pacemakers.